Spherically trained platform



March 28, 1967 o. OKLAND ETAL 3,311,336

SPHERI CALLY TRAINED PLATFORM Filed Oct. 28, 1964 2 Sheets-Sheet 1 OLAV OKLAND HAROLD W. HAIGHT INVENTORS A TTORNEY March 28, 1967 o. OKLAND ETAL 3,311,336

SPHERICALLY TRAINED PLATFORM 2 Sheets-Sheet 2 Filed Oct. 28, 1964 DISPLACING FORCE DISPLACING FORCE OLAV OKLAND HAROLD W. HAIGHT INVENTORS ATTORNEY United States Patent 3,311,336 SPHERTCALLY TRATNED PLATFGRM iav {)Hand, Riverside, and Harold i Haight, Corona, Calih, assignors to the United States of America as represented by the Secretary of the Navy Filed Oct. 2%, 1964, Ser. No. 457,266 Claims. ((31. 248-163) The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to antennas, and more particularly to a simple plat-form that will train and maintain an axis perpendicular to a spherical surface.

Previously a double rack and carriage arrangements with drives in both horizontal and vertical planes have been used. However, these previous arrangements required critical machining tolerances and fittings in numerous places, and were difiicult to assemble and properly adjust.

In the present invention an antenna to be trained and a free gyro are mounted on a gimballed platform which is positioned by a rod that passes through a ball joint in a spherical concave dish. The orientation of the platform is maintained by three equal length legs which bear on the spherical dish. This symmetrical device provides a simpler and more positive arrangement than the unsymmetrical double curved rack and carriage devices previously used. The instant device can also be packaged within a smaller diameter than previous devices.

It is an object of the invention, therefore, to provide a novel spherically trained platform assembly for antennas and the like.

Another object of the invention is to provide a simple platform that will train and maintain an axis perpendicular to a spherical surface.

A further object of the invention is to provide a platform to track around a spherical surface while maintaining an antenna face or the like perpendicular to the axis through the center of and at a constant distance from the center of the sphere.

Other objects and many of the attendant advantages of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a top View of an embodiment of the inven tion substantially in cross-section taken along line 1-1 of FIG. 2 with the platform of the assembly centered.

FIG. 2 is a front end View of the invention.

FIG. 3 is a top view of the invention with the platform in a displaced position.

FIG. 4 is a side view of the invention with the platform in a displaced position.

Referring now to the drawings, like numerals refer to like parts in each of the figures.

As shown in the drawings, an antenna array 14) or the like and a free gyro 11, for example, are mounted on a platform 13, which is gimballed to and positioned by a rod 15. Girnbals 14 are attached to the end of rod 15 at 16 for the mechanical connection between platform 13 and rod 15. Rod 15 passes through and is supported by a spherical bearing or gimbal arrangement 17 at the center of a concave spherical dish 19. The orientation of platform 13 with its central axis always perpendicular to the spherical surface of dish 19 is maintained by three equal length supports or legs 20 bearing against the inner spherical surface of dish 19. Positioning in the horizontal and vertical directions is accomplished by displacing rod 15 by the application of forces in the appropriate direc- Patent-ed Mar. 2 1967 tion as in FIGS. 3 and 4. A spring 22 or similar means maintains the tips 21 of all three legs 24 bearing against the inner surface of dish 19. The tips 21 may be made of nylon or the like for ease in moving over the spherical surface. As the platform 13 is moved by displacing the rod, as in FIGS. 3 and 4, the rod passes slightly further through spherical bearing 17 and spring 22 is compressed. When forces displacing rod 15 are removed, spring 22 tends to center the platform axis along the axis of the assembly by returning to its normal position as in FIG. 1. The antenna and gyro platform 13 are counterbalanced by means of a weight 23, for example, to minimize the positioning force requirements. Positioning requirements can be from a remotely received signal in a tracking function or the platform 13 can be positioned by a manual or automatic control signal. Gyro 11 can be used to provide displacement readout information where desired.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A spherically trained platform assembly for tracking about a spherical surface while maintaining the platform axis perpendicular to the spherical surface, comprising:

(a) a spherical dish,

(b) a first gimbal arrangement mounted in the center of the surface of said spherical dish,

(0) a rod extending through and being supported by said first gimbal arrangement,

((1) a platform having three supporting legs which movably bear against the inner surface of said spherical dish and which always maintain the central axis of said platform perpendicular to the spherical surface of said dish,

(e) a second gimbal arrangement,

(f) said platform being attached by means of said second gimbal arrangement to the end of said rod extending inside the spherical dish,

(g) said platform being movable in both horizontal and vertical directions while maintaining its central axis always perpendicular to the spherical surface of said dish by appropriate non-axial forces against the other end of said rod which extends outside said spherical dish.

2. A device as in claim 1 wherein said first gimbal arrangement is a spherical bearing.

3. A device as in claim 1 wherein the other end of said rod opposite said platform end is counterbalanced to minimize the force requirements for positioning said gimballed platform.

4. A device as in claim 1 wherein the tips of said supporting legs are nylon bearings for ease in gliding over said spherical dish surface.

5. A device as in claim 1 wherein means is provided for maintaining the tips of all three said supporting legs always bearing against the spherical surface of said dish and for tending to center the gimballed platform axis with the assembly axis when said non-axial positioning forces are removed.

References Cited by the Examiner UNITED STATES PATENTS 3,009,152 11/1961 Gregory et al. 745.22 X 3,084,342 4/1963 Fuller et al 74-5.22 X

FRED C. MATTTERN, IR., Primary Examiner. I. D. PUFFER, Assistant Examiner. 

1. A SPHERICALLY TRAINED PLATFORM ASSEMBLY FOR TRACKING ABOUT A SPHERICAL SURFACE WHILE MAINTAINING THE PLATFORM AXIS PERPENDICULAR TO THE SPHERICAL SURFACE, COMPRISING: (A) A SPHERICAL DISH, (B) A FIRST GIMBAL ARRANGEMENT MOUNTED IN THE CENTER OF THE SURFACE OF SAID SPHERICAL DISH, (C) A ROD EXTENDING THROUGH AND BEING SUPPORTED BY SAID FIRST GIMBAL ARRANGEMENT, (D) A PLATFORM HAVING THREE SUPPORTING LEGS WHICH MOVABLY BEAR AGAINST THE INNER SURFACE OF SAID SPHERICAL DISH AND WHICH ALWAYS MAINTAIN THE CENTRAL AXIS OF SAID PLATFORM PERPENDICULAR TO THE SPHERICAL SURFACE OF SAID DISH, (E) A SECOND GIMBAL ARRANGEMENT, (F) SAID PLATFORM BEING ATTACHED BY MEANS OF SAID SECOND GIMBAL ARRANGEMENT TO THE END OF SAID ROD EXTENDING INSIDE THE SPHERICAL DISH, (G) SAID PLATFORM BEING MOVABLE IN BOTH HORIZONTAL AND VERTICAL DIRECTIONS WHILE MAINTAINING ITS CENTRAL AXIS ALWAYS PERPENDICULAR TO THE SPHERICAL SURFACE OF SAID DISH BY APPROPRIATE NON-AXIAL FORCES AGAINST THE OTHER END OF SAID ROD WHICH EXTENDS OUTSIDE SAID SPHERICAL DISH. 